title: Cognitions and Insomnia Subgroups.
abstract: OBJECTIVE
  This study explored cognitive predictors of multiple symptoms of insomnia (difficulty with sleep initiation, maintenance, and early morning awakenings) among a sample of individuals seeking cognitive-behavior therapy for insomnia.
  
  
  METHODS
  Participants consisted of 146 clinical patients with insomnia of which 67 (45.89%) were classified as Single Symptoms subgroup and 79 (54.11%) as Combined subgroup. A receiver operating curve (ROC) analysis was conducted to identify predictors of Combined versus Single Symptom subgroups. The set of predictor variables included demographics, sleep-related cognitions, circadian preferences, depression symptoms, and self-report sleep parameters with insomnia subgroups (Combined versus Single Symptom only) as the dependent variable.
  
  
  RESULTS
  The ROC analysis identified two significant predictors: Self Efficacy Scale (SES) < 23 and a 3-item subscale of the Glasgow Content of Thoughts Inventory (GCTI) assessing "thoughts about the environment" with scores ≥ 5. Post-hoc comparisons revealed that individuals with combined symptoms who had SES score < 23 had significantly longer sleep onset latency (SOL) and more number of nights with SOL>30 minutes, poorer sleep quality, higher insomnia severity, less morningness tendency, higher depression symptom severity, and more anxiety about anxiety and about sleep compared to individuals with SES score ≥ 23.
  
  
  CONCLUSIONS
  These findings indicate that low self-efficacy and increased thoughts about the environment are associated with having multiple symptoms of insomnia. Further research should examine the specific role of self-efficacy and thought content in the etiology of individuals who suffer from multiple symptoms of insomnia.
authors.affiliation: Stanford University School of Medicine, Department of Psychiatry and Behavioral Science, Stanford CA 94301.
authors.forename: Sooyeon
authors.initials: S
authors.lastname: Suh
authors.forename: Jason C
authors.initials: JC
authors.lastname: Ong
authors.forename: Dana
authors.initials: D
authors.lastname: Steidtmann
authors.forename: Sara
authors.initials: S
authors.lastname: Nowakowski
authors.forename: Claire
authors.initials: C
authors.lastname: Dowdle
authors.forename: Erika
authors.initials: E
authors.lastname: Willett
authors.forename: Allison
authors.initials: A
authors.lastname: Siebern
authors.forename: Rachel
authors.initials: R
authors.lastname: Manber